Radial drilling machine



Dec. 29, 1970 H. MULLER RADIAL DRILLING MACHINE Filed Aug. 28, 1968 l Il L I I INVENTOR H ELLMUT m u LLPEK United States Patent 3,550,480RADIAL DRILLING MACHINE Hellmut Miiller, 91 Esslinger Strasse, 731Plochingen (Neckar), Germany Filed Aug. 28, 1968, Ser. No. 755,985 Int.Cl. B2311 39/12 U.S. Cl. 77-28 7 Claims ABSTRACT OF THE DISCLOSURE Aradial drilling machine includes a base frame and a vertically extendingcolumn of circular cross-section mounted for turning in the base frameand for movement up and down therein. A clamping arrangement is providedwhich can be clamped to or'released from the column to permit turningand which slides up and down in the frame while engaging a guide whichprevents it from turning around the axis of the column. The top of thecolumn carries a cantilever. arm mounted on rollers for horizontal backand forth movement with a boring head at one end and a motor and gearingat the other.

The invention is concerned'vvith a radial drilling machine and moreparticularly with a machine which has a vertical column with a circularcross section supported or a base frame so as to be rotatable and aroundits vertical axis and movable up and down. Radial drilling machines ofthe category characterized above and already known per se are lessexpensive in their construction than other known comparable arrangementswhich have a column rigidly and unrotatably supported on the said baseframe and having a roller box rotatably arranged on the said column.However, these known arrangements have the disadvantage that the column,whilst moving up and down, may turn round so that the relative positionin a horizontal plane between the tool and the work piece may be lost.However, with these machines to guide the column so as to render anyrotatory motion impossible, would prevent the rotatory motion of thecolumn and disadvantageously influence the function of the mechanism.

It is, therefore, an object of the present invention to avoid the abovedrawbacks and to reduce building expenses for the machine in question.

To obtain this, another object of the invention is to provide a sectionof that part of the column which is accommodated within the base frameto be'embedded in a holding device that surrounds partially at least thecolumn and that is guided for an up and down movement along a verticalguide by means of a suitable extension and that can be rigidly lockedwith, and unlocked from, the column.

Yet another object of the invention is to provide a r machine of theaforesaid kind which allows on the one hand to go up and down with thecolumn and to thereby maintain the exact relative position and on theother hand to selectively lock the column with the said base frame ormake it rotatable about its longitudinal axis.

Another object of the invention is to obtain an easy rotation of thecolumn without using constructive elements that are too costly.

A further object of the invention is to provide a machine of the kindhere in question with which cantilever arm carries on its one end theboring head and on its other end the driving motor andif necessary-thegear to be interposed between the motor and the boring head. Withcantilever arms constructed in the usual manner that have their weightsunevenly distributed, it is possible that the column and the cantileverarm so disadvantageously presses against that part of the supportingframe "ice which has to bear the column that the relatively highpressure components and the high frictional forces might disturb therotatory movement of the column unless expensive antifriction bearingsare used. This drawback is eliminated by the present invention becausethe distribution of weights obtained in the above described wayaccording to the invention results in almost equal loads on both ends ofthe cantilever arm, whereby a unilateral stress or load is avoided atthe point where the column is supported by the base frame.

These and other objects, features, and advantages of the presentinvention will become further apparent from the following detaileddescription thereof, particularly when the same is read with referenceto the accompanying drawings, in which:

FIG. 1 is a first form of embodiment of a radial drilling machineaccording to the invention in a schematical side view and in a partlyvertical section,

FIG. 2 is a section taken along the line II--II in FIG. 1 of thearrangement according to FIG. 1,

FIGS. 3, 4 and 5 are side views partly in section of details of threemodified forms of embodiment of the radial drilling machine according toFIG. 1.

The radial drilling machine shown in FIG. 1 has a column 1 which isrotatably supported on the base frame 2 at 3 and 4, and which can bemoved up and down, for example, by means of the threaded spindle 5 andthe nut 6, for instance, with the help of the driving wheel 7. At theupper end the column is rigidly connected with the roller box 8, withinwhich the cantilever arm 9 together with the boring head 10 is guided soas to be displaceable to and fro longitudinally according to the arrow11, in a manner known per se. The cantilever arm 9 runs on three pairsof rollers 40a, 40b, 40c mounted on the roller box 8 and is fixed andclamped in its position conveniently by being pressed against a slideway connected with the roller box by an appropriate clamping mechanism41. The column 1 can be moved up and down according to the arrow 12. Itis rigidly connected with the base frame by means of the column clampingmechanism 42.

In order to ensure on the one hand that the column is guided securelyand unrotatably during the vertical up and down displacement of thecolumn according'to the arrow 12 and to make possible, if necessary, onthe other hand, a rotational movement of the column about itslongitudinal axis 13 according to arrow 14, a section of that part ofthe column which is within the base frame 2 has been embedded accordingto the invention at least along a part of the periphery of the columninto a holding device 15 that is guided so as to be movable up and downby means of a shoulder gliding along a vertical guide 16, and that canbe locked with the column so as to be unrotatable or can be unlockedfrom it so that the rotational motion of the column around itslongitudinal axis 13 may be prevented or may be made possible. Hereby,the holding device can be rigidly connected with the column by means ofa clamping connection which in its ineffective position allows arotation of the column around its longitudinal axis with respect to theholding device. With the embodiment according to FIGS. 1 and 2 theholding device consists of a plate-like form piece 15 that convenientlyextends in a plane rectangular to the longitudinal axis 13 of thecolumn, and which surrounds at one end the column as shown at 17,whereas at the other end it slidingly engages on the vertical guide bar16. This vertical guide bar may have a circular cross section and may beafiixed to the base frame. The respective connections, for instance fivein our drawing, are represented at 18. The said guide bar is embraced bythe bifurcated end of the holding device with two projections orextensions 19 and 20. and this holding device can be fixed in anyposition desired without clearance by means of the regulating oradjusting screw 21. The holding device can also slidingly embrace theguide bar by means of a ball bearing like part. With another embodimentof the invention the guide bar has on the side facing the column a crosssection like an U and the holding device is guided with a pivot on thisU-like guide. The form piece 15 surrounds the column ring-like and hason one side a slot 22 extending radially with respect to thelongitudinal axis 13 of the column, whereby the ends 22a, 22b of thering surrounding and enclosing the column can be clamped against eachother in the zone of the slot in order to get a clamping connectionbetween the holding device and the column by means of at least one screw23 or by means of springs, magnets, by means of a hydraulic arrangement,etc., whereby the clamping force acts in a direction tangential to thepeirphery of the column. The breadth of the plate-like holding device 15decreases from an amount that slightly surpasses the diameter of thecolumn 1 to an amount that is a little greater than the diameter of theguide bar 16, whereby the border zones 24a, 24b extend obliquely withapproximatively the same angle with respect to a vertical plane, andwhereby the shoulders or extensions 22a, 2212 which are held together bythe screw 23 extend radially with respect to the column. This plate-likeform piece is conveniently arranged on the lower end of the column 1.

With the conventional radial drilling machines the motor 43 and the gear44 are attached to the boring head as indicated by the dotted lines. Itcan be realized that in this case and in particular when the cantileverarm has been displaced in outward direction the pressure exerted on theside facing the boring head of the bearing 4 and on the side turned awayfrom the boring head of the bearing 3 is especially great, whereby thefriction is increased and the rotatory movement is impeded ordetrimentally influenced. In such cases there are eventually expensiveantifriction bearings necessary. The change of the position of the motoras well as of the gear as indicated at 45 and 46 results in a balance ofweight and consequently in a reduction of the pressure on the bearingsurfaces and, therefore, in facilitating the rotatory movement so thateventually antifriction bearings are no more necessary.

With the embodiment according to FIG. 3 the holding device is againplate-like shaped, whereby it surrounds the column 25 like a ring. Thiscolumn has a single longitudinal slot 27 or several slots beginning atthe lower end of the column and extending vertically upwards in thedirection of the longitudinal axis 26 of the column. By means of thisslot or these slots the circumference of the column can be expanded sothat the column and the holding device are clamped with each other.

With the embodiment according to FIG. 4 an electromagnetic shaftcoupling known per se serves for locking or clamping the holding device47 With the column 48, whereby the part 38 of the coupling is rigidlyconnected with the column 48 and the coupling part 37 is rigidlyconnected with the holding device 47. By switching in or out theelectric current the column can selectively be rigidly locked with theholding device or unlocked therefrom.

As can be seen the guiding elements for the column and the holdingdevice are removably attached to the base frame respectively to thecolumn. Therefore, the radial drilling machine can be delivered and usedwith and without the holding device and the guiding elements accordingto the necessities of the users, whereby the holding device representinga constructive group for itself can be mounted without difiiculties tothe machine.

It is suitable to actuate the clamping connections between the columnand the holding device represented in FIGS. 2 to 5 by some remotecontrol whether mechanical or electro-motive 0r electro-magnetic orhydraulic or pneumatic.

The device operates in the following manner: Whenever it is desirable tomaintain the position during the up and down movement of the column, thecantilever arm and the holding device are locked in their position,whereas the clamping mechanism 42 for the column is released during theup and down movement of the column. It is recommendable to use for thatpurpose one of the remote controls mentioned above. During the operationitself, for instance, when boring it is suitable and convenient toactuate and lock the clamping mechanism 42 for the column, too. Allclamped connections are loosened, and" released, if the machine has topass over from a certain working position to another one.

It is of advantage for certain Working operations to make thearrangement, for example, by a serial connection of electric relays suchthat with the actuation of the push button Up or Down of the remotecontrol, the holding device is blocked first, in order to have, for theup and down movement, a column that cannot swing or rotate at all.

Although my invention has been illustrated and described with referenceto the preferred embodiments thereof, 1 wish to have it understood thatit is in no way limited to the details of such embodiments, but iscapable of numerous modifications within the scope of the appendedclaims.

Having thus fully disclosed my invention, what I claim is:

1. A radial drilling machine comprising in combination: a base frame; avertically extending column of circular cross-section mounted on saidbase-frame for rotational movement about its longitudinal axis andmovable up and down in vertical direction; drive means carried by saidbase-frame and operatively engaging said column for imparting to saidcolumn vertical up and down movement; a roller box attached to the upperend of said column, said roller box containing several guide rollers; acantilever arm arranged at the upper end of said column and extendingtransverse to the said column, guide rollers on said roller box guidingthe said cantilever arm so as to be displaceable in longitudinaldirection; a tool carrying boring head supported on the one end of saidcantilever arm; the said column having a portion contained within thesaid base frame, a holding device enclosing the said portion at leastalong a part of the periphery of the said column, said holding devicehaving an extension, a vertical guide on said base frame, said extensionoperatively engaging said vertical guide so as to be vertically movableup and down.

2. The radial drilling machine set forth in claim 1, wherein the saidcantilever arm carries on its other end the driving motor and the gearconnecting the said driving motor and the said boring head.

3. The radial drilling machine set forth in claim 1, wherein a clampingdevice is provided for connecting said holding device rigidly with thesaid column, said clamping device allowing in its inoperative position arotation of the said column with respect to the said holding deviceabout the longitudinal axis of the said column.

4. The radial drilling machine set forth in claim 1, wherein the saidholding device comprises a plate-like piece extending at leastprincipally in a plane which is perpendicular to the longitudinal axisof the column, said holding device embracing with its one end the saidcolumn and slidingly engaging with its other end the vertical guide.

5. The radial drilling machine set forth in claim 4, wherein the saidvertical guide comprises a guide bar attached to the said base frame andengaged by a forklike end of the holding device, the said connectionbetween the said fork-like end of the said holding device and the saidguide bar being adjustable by means of a screw means extending radiallyto the axis of the said bar.

6. The radial drilling machine set forth in claim 5, column in order toestablish a clamping connection wherein the plate-like piececonstituting the said holdbetween the said holding device and the saidcolumn. ing device is arranged on the lower end of the said column.

7. The radial drilling machine set forth in claim 6, References Citedwherein the piece constituting the said holding device encloses the saidcolumn and has a through-slot extending radially to the longitudinalaxis of the said column, where- FRANCIS S. HUSAR, Primary Examiner bythe two ends of the ring enclosing the said column may be pressedagainst one another by means of a clamping force directed approximatelytangentially to the said 10 1436 5 German Printed Application,1,208,976, Jan. 13, 1966.

